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Polymorphs and Polymorphic Cocrystals of Temozolomide
Chemistry – An Asian Journal, 2008AbstractCrystal polymorphism in the antitumor drug temozolomide (TMZ), cocrystals of TMZ with 4,4′‐bipyridine‐N,N′‐dioxide (BPNO), and solid‐state stability were studied. Apart from a known X‐ray crystal structure of TMZ (form 1), two new crystalline modifications, forms 2 and 3, were obtained during attempted cocrystallization with carbamazepine and 3‐
N Jagadeesh, Babu +3 more
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Chemical Reviews, 2013
An unambiguous definition of conformational change and conformational polymorphism, as well as a quantitative basis for the likelihood of its appearance, is reviewed. Conformational adjustment and conformational change are different phenomena. Two polymorphs are conformational polymorphs only if their conformations are related by conformational change.
Cruz-Cabeza, A.J., Bernstein, J.
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An unambiguous definition of conformational change and conformational polymorphism, as well as a quantitative basis for the likelihood of its appearance, is reviewed. Conformational adjustment and conformational change are different phenomena. Two polymorphs are conformational polymorphs only if their conformations are related by conformational change.
Cruz-Cabeza, A.J., Bernstein, J.
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On the Polymorphism of Aspirin
Angewandte Chemie International Edition, 2007More headaches with aspirin: No new polymorph? Reduction and re-indexing of X-ray data collected on a crystal of the well-known form I of aspirin in a unit cell recently reported for the new form II results in a data set from which this so-called new form can be obtained and even refined isotropically! Form II, if it exists, needs to be identified with
Bond, Andrew +2 more
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Acta Crystallographica Section C Crystal Structure Communications, 1996
The title compound, 7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diyl diacetate, C21H23NO5, was crystallized from a solution of its hydrochloride and sodium acetate. Unlike prior reports in which crystals were hexagonal shaped (orthorhombic) and in space group P2(1)2(1)2(1), the crystals in the present determination grew as large prisms (monoclinic ...
J R, Deschamps +2 more
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The title compound, 7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diyl diacetate, C21H23NO5, was crystallized from a solution of its hydrochloride and sodium acetate. Unlike prior reports in which crystals were hexagonal shaped (orthorhombic) and in space group P2(1)2(1)2(1), the crystals in the present determination grew as large prisms (monoclinic ...
J R, Deschamps +2 more
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Journal of Pharmaceutical Sciences, 2002
Roxifiban was found to exist in two polymorphic forms. The polymorphs were detected by X-ray powder diffraction and solid-state carbon nuclear magnetic resonance. A slight difference between the two polymorphs was also detected by isothermal microcalorimetry. However, no differences were observed by differential scanning calorimetry, infrared, or Raman
Michael B, Maurin +7 more
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Roxifiban was found to exist in two polymorphic forms. The polymorphs were detected by X-ray powder diffraction and solid-state carbon nuclear magnetic resonance. A slight difference between the two polymorphs was also detected by isothermal microcalorimetry. However, no differences were observed by differential scanning calorimetry, infrared, or Raman
Michael B, Maurin +7 more
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Molecular and General Genetics MGG, 1967
Single inseminated founder females in D. melanogaster derived from the same population have led to genetically discrete strains for three quantitative traits, namely scutellar chaeta number, mating speed and duration of copulation. The base population from which the females were derived can therefore be argued to be polymorphic for these traits ...
P A, Parsons, S M, Hosgood, B T, Lee
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Single inseminated founder females in D. melanogaster derived from the same population have led to genetically discrete strains for three quantitative traits, namely scutellar chaeta number, mating speed and duration of copulation. The base population from which the females were derived can therefore be argued to be polymorphic for these traits ...
P A, Parsons, S M, Hosgood, B T, Lee
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Acta Crystallographica Section C Crystal Structure Communications, 2001
Pentacene, C(22)H(14), crystallizes in different morphologies characterized by their d(001)-spacings of 14.1, 14.5, 15.0 and 15.4 A. We have studied the crystal structure of the 14.1 and 14.5 A d-spacing morphologies grown by vapour transport and from solution. We find a close correspondence between the 14.1 A structure reported by Holmes, Kumaraswamy,
Mattheus, C. C. +5 more
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Pentacene, C(22)H(14), crystallizes in different morphologies characterized by their d(001)-spacings of 14.1, 14.5, 15.0 and 15.4 A. We have studied the crystal structure of the 14.1 and 14.5 A d-spacing morphologies grown by vapour transport and from solution. We find a close correspondence between the 14.1 A structure reported by Holmes, Kumaraswamy,
Mattheus, C. C. +5 more
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Polymorphism of clarithromycin
Archives of Pharmacal Research, 2000It is well recognized that physicochemical properties of drugs are affected by the type of polymorphic crystalline form of drugs. Clarithromycin is known to exist in at least three polymorphic crystalline forms. Since conventional means to obtain the most thermodynamically stable form (Form II) for the antibiotics is known to be associated with a low ...
Y T, Sohn, J K, Rhee, W B, Im
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Polymorphism of Spironolactone
Journal of Pharmaceutical Sciences, 1991Single crystals of two polymorphic and four solvated crystalline forms of spironolactone (C24H32O4S) were obtained using different solvents. The morphology, symmetry, and crystallographic parameters were determined for all crystal forms except for the one obtained from methanol.
V, Agafonov +4 more
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Journal of the American Chemical Society, 2004
The complex formed between 4-methylpyridine and pentachlorophenol (4MPPCP) crystallizes in a triclinic space group. If the same complex is synthesized from deuterated pentachlorophenol (4MPPCP-d1), it crystallizes in an entirely different monoclinic polymorph.
Jun, Zhou +2 more
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The complex formed between 4-methylpyridine and pentachlorophenol (4MPPCP) crystallizes in a triclinic space group. If the same complex is synthesized from deuterated pentachlorophenol (4MPPCP-d1), it crystallizes in an entirely different monoclinic polymorph.
Jun, Zhou +2 more
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